X-108582884-G-T

Variant names:

• chrX-108582884-G-T
• rs104886084
• NM_033380.3:c.937G>T

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_033380.3(COL4A5):​c.937G>T​(p.Gly313Cys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 14/23 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G313R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: COL4A5 NM_033380.3 missense, splice_region
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.81
• Publications: 0 publications found

Genes affected

COL4A5 (HGNC:2207): (collagen type IV alpha 5 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. Mutations in this gene are associated with X-linked Alport syndrome, also known as hereditary nephritis. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. Alternatively spliced transcript variants have been identified for this gene. [provided by RefSeq, Aug 2010]

COL4A5 Gene-Disease associations (from GenCC):

• Alport syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen, G2P
• X-linked Alport syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Genomics England PanelApp, Myriad Women’s Health, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 2 uncertain in NM_033380.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-108582884-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 3572993.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 538 curated pathogenic missense variants (we use a threshold of 10). The gene has 138 curated benign missense variants. Gene score misZ: 2.4995 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to X-linked Alport syndrome, Alport syndrome.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant X-108582884-G-T is Pathogenic according to our data. Variant chrX-108582884-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1077048.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL4A5	NM_033380.3	c.937G>T	p.Gly313Cys	missense_variant, splice_region_variant	Exon 17 of 53	ENST00000328300.11	NP_203699.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL4A5	ENST00000328300.11	c.937G>T	p.Gly313Cys	missense_variant, splice_region_variant	Exon 17 of 53	1	NM_033380.3	ENSP00000331902.7
COL4A5	ENST00000483338.1	c.-240G>T		5_prime_UTR_variant	Exon 1 of 20	1		ENSP00000495685.1
COL4A5	ENST00000361603.7	c.937G>T	p.Gly313Cys	missense_variant, splice_region_variant	Exon 17 of 51	2		ENSP00000354505.2

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Feb 22, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Gly313 amino acid residue in COL4A5. Other variant(s) that disrupt this residue have been observed in individuals with COL4A5-related conditions (PMID: 16941480, 33330536), which suggests that this may be a clinically significant amino acid residue. This variant disrupts the triple helix domain of COL4A5. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL4A5, missense variants at these glycine residues are significantly enriched in individuals with disease (PMID: 23720012, 27627812) compared to the general population (ExAC). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. ClinVar contains an entry for this variant (Variation ID: 1077048). This variant has not been reported in the literature in individuals affected with COL4A5-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 313 of the COL4A5 protein (p.Gly313Cys). -

X-linked Alport syndrome Pathogenic:1

-

Precision Medicine Center, Zhengzhou University

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PM1:Located in a mutational hot spot PM2:not found in gnomAD PP2:Missense variant in a gene that has a low rate of benign missense variation and in which missense variants are a common mechanism of disease PP3:Multiple lines of computational evidence support a deleterious effect on the gene or gene product -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.94	.;D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	4.4	H;H
PhyloP100		7.8
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-8.4	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.91
MutPred		1.0		Loss of relative solvent accessibility (P = 0.0676);Loss of relative solvent accessibility (P = 0.0676);
MVP		1.0
MPC		0.32
ClinPred		1.0	D
GERP RS		5.7
PromoterAI		0.014	Neutral
Varity_R		1.0
gMVP		1.0
Mutation Taster		=17/83	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs104886084; hg19: chrX-107826114;